An estimated 1 in 6 men will be diagnosed with prostate cancer (PCa). Although the majority of these men can be successfully treated with surgery or radiation therapy, approximately 20%-40% will biochemically recur within 10 years of treatment. This risk of recurrence is elevated to approximately 50% for men with locally advanced disease, a condition that is primarily managed by radiation therapy. Thus, there is a need for new technologies that improve the therapeutic index of radiation therapy for local disease because these will significantly decrease the morbidity and mortality of PCa.